1. Field of the Invention
The present invention relates to insulated electrical conductors that may be used in data cables, such as twisted pair cables, and in particular to insulated conductors that are geometrically optimized for superior performance.
2. Discussion of the Related Art
Data and other communication cables, such as, for example, shielded or unshielded twisted pair cables often include several insulated conductors for carrying electrical signals. Referring to FIG. 1, there is illustrated, in widthwise cross-section, one example of a conventional insulated conductor 100. The insulated conductor comprises a round metal core 102 surrounded by an insulating layer 104 that is also substantially circular in cross-section, as illustrated.
When two conventional insulated conductors 100 are twisted together to form a twisted pair, the conventional round insulated conductors do not stay in physical contact along their entire lengths, but rather tend to nest in some places and separate in others along their twisted length. This results in a variable air gap between the two conductors along the length of the twisted pair, which affects the impedance of the twisted pair. For example, for insulated conductors having a 0.035 inch diameter, there is generally a 0.002-0.004 inch variation in the air gap between the conductors along their twisted length, resulting in a rough impedance over the operating frequency of the twisted pair.